5.1 Log Data Problem

[mmarien]

I designed an AFR gauge for my oxygen sensor:

dynonavionics.com/cgi-bin/yabb2/YaBB.pl?num=1268164287/29#12

The oxygen sensor output is 0-5V and the gauge seems to work fine but the log data output is a steady 9.999. It should read between 13 and 15.

Did you ever come up with a generic sensor. Same thread reply#16.

 

[dynonsupport]

Can you post a few lines of your log file and tell us which column you are looking at?

We have not added any more generic sensor types.

 

[mmarien]

Attached is partial file of the black box log. Column CU is called AFR Volts which I believe is showing info from pin C37_P31.

From the senor (sfg) file:

sensor={
     id=AIR FUEL RATIO
     function=VOLTS
     pins=C37_P8 C37_P22 C37_P31
     name=AFR
     min_val=10.0
     max_val=20.0
     resolution=1
     round=0.1
     is_piecewise=0
     low_coeff={
           c_x4=0
           c_x3=0
           c_x2=0
           c_x1=2.0
           c_x0=10.0
           }
     low_resistance=NONE
     low2high_cross=0
     high_coeff={
           c_x4=0
           c_x3=0
           c_x2=0
           c_x1=0
           c_x0=0
           }
     high_resistance=NONE
     high2low_cross=0
     window=.2
     shift=3
     age=16
     }

from the display (dfg) file:

      c37_p31={
            valid=1
            name=AFR
            id=AIR FUEL RATIO
            alarm_type=OFF
            range={
                  max_display=17
                  min_display=10
                  range1_valid=1
                  range1_top=17.5
                  range1_bot=16
                  range1_name=R1
                  range1_color=RED
                  range2_valid=1
                  range2_top=16
                  range2_bot=15
                  range2_name=R2
                  range2_color=YELLOW
                  range3_valid=1
                  range3_top=15
                  range3_bot=12.5
                  range3_name=R3
                  range3_color=GREEN
                  range4_valid=1
                  range4_top=12.5
                  range4_bot=11.5
                  range4_name=R4
                  range4_color=YELLOW
                  range5_valid=1
                  range5_top=11.5
                  range5_bot=10
                  range5_name=R5
                  range5_color=RED
                  }
            }

Screen shot:

 

[mmarien]

Bump

 

[mmarien]

No fix in version 6.0  I'm getting anxious to plot my AFR against EGT's with savvy analysis.

 

[dynonsupport]

So it turns out that's an issue with devices designated as "voltage" where we assume you want a lot of decimal precision so we give you 0.000-9.999. The system isn't dynamic enough to look at what you want and adjust the ranges intelligently. It would be a lot of work to change this for a variety of reasons, so this isn't something we're likely to work on unless we get a lot of demand.

You have two easy fix options:
1) Call the sensor a pressure sensor, not voltage. Now it will say AFR PSI instead of AFR VOLTS, but it will work on the screen and in the datalog perfectly (I tried it here myself)

2) Keep it as volts, but do everything in 1/10th scale, so an AFR of 14.7 is 1.47. Once in excel you can multiply this by 10 before any analysis or uploading to Savvy.

 

[mmarien]

Thanks. I'll try those a try and see which will work for me.

 

[mmarien]

That worked. I made it a pressure sensor.

https://www.savvyanalysis.com/flight/315530/7408edec-4b42-40c9-b8c3-58c7b0a7e6f6

The spikes in AFR at cruise are switching fuel pumps to check they both work.